Figure 2
Experimental setup for constructing and characterizing the carpet-like devices.
A light beam with wavelength λ = 632.8 nm from a He-Ne laser is divided into three parts: object light W, reference light R and reconstruction light S by beam splitters B1 and B2. M1-M5 are mirrors, E1 and E2 are beam expanders, S1, S2 and S3 are the shuttles, L is a lens with focal length f = 10 cm, P0, P1 and P2 are planes for recording plate, objects O1 and O2, respectively. The distance between object plane P1 and L is 20 cm, which equals to the distance between L and P0. So P0 is the one-to-one image plane of P1. The pinhole is used to block the stray light. A charge-coupled device (CCD) placed 20 cm away behind O1 is used to take images of objects and monitor the characterization of carpet-like devices. A cross mark is placed between the CCD and object plane P1 as a reference mark for monitoring the effect of the carpet-like devices on other objects nearby O1. The x-y plane of coordinate system is parallel to P1 and the z axis direction is anti-parallel to the light beam W. In exposure process, shuttles S1 and S2 are opened but S3 is closed, while in the process of characterizing the effects of finished carpet-like devices, shuttles S1 and S2 are closed but S3 is opened.
